I don't think we've really solved this mystery yet. Note that the attribution says "Edited by Seiseki Abe", not translated. I have met Abe Sensei, even received instruction from him on the mat, and he never attempted to speak a word of English to me. Unless he was hiding it very well, I would say that he doesn't have any significant ability to write English. Perhaps one of his students did these translations, but they put sensei's name as the editor out of respect?